Dr. Universe: How is glass made? And, what is it made out of? What about thick glass like they are putting up on the Space Needle? – Tali, almost 8 years old, Seattle, Wash.

Dear Tali,

We can make glass in factories and we can find it in nature. Some volcanoes make glass. When they spew out lava, it often cools into obsidian, a black glass. Glass can also form on sandy beaches. Small tubes with smooth glass on the inside may appear after super-hot lightning strikes the sand. » More …

Dr. Universe: How do planes fly? -Tahira, 12, India

Dear Tahira,

Planes are very heavy, yet they stay up in the air kind of like a bird in the sky. They can get us across the world in less than a day. Humans went from learning how to fly a plane to putting a man on the moon in a little over 60 years.

But the answer to your question goes even further back. It goes all the way back to the 1700s and actually started not with air, but with water.

That’s what I found out from my friend Michael Allen, a physics and astronomy professor at Washington State University. He thought you asked a great question and was happy to tell me all about how planes can fly.

Around 300 years ago, a scientist from Switzerland named Daniel Bernoulli was experimenting with water pipes, like the ones under your sink at home. When water (or anything) moves through a small space, like the inside of a pipe, it puts pressure on that container (the pipe.)

The more air you push into a smaller space, the greater the pressure. Allen told me that Bernoulli found out that the faster the water moved through the pipe, the less pressure the water put on the pipe.

This idea has come to be known as Bernoulli’s Principle. This principle doesn’t only apply only to water, it also applies to air that passes over the wings on an airplane.

Allen told me that wings on an airplane are flat on the bottom and curved on the top. Allen said that as the wing moves through the air, some air goes over the top of the wing while some goes under the bottom of the wing.

However, the air that goes over the top of the wing has to go over a longer distance than the air under the wing because of the curve. Allen also said the air has to get past the wing at the same time, meaning the air above must travel faster, just like the water moving quickly in the pipe.

Since this air above the wings travel faster, there is less pressure above the wing than below the wing, which pushed the wings and the plan up into the air, causing the plane to fly.

Thanks for your question. It was a great one and I’m happy that you have such a big interest in airplanes. Have you ever thought about becoming a scientist or engineer that works on planes one day? Maybe you could make the next spacecraft that takes a person to the moon or Mars.

Sincerely,
Ian Smay and Dr. Universe

Ianb Smay contributed this article. He is a student in the Edward R. Murrow College of Communication at Washington State University.

Hello Dr. Universe, may I ask how fish breathe? – Nghi, 11, Vietnam

Hello Nghi,

Cats, humans, and fish all breath for the same reason. We need oxygen. Oxygen is one of the things our bodies use to make energy.

Just like the hungry feeling you get when you haven’t eaten, your body uses oxygen to keep everything running. Unlike the breaks you take between meals, the breaks you take between breathes are much shorter. Most people take about 12 breaths per minute.

While it may seem like we breath only oxygen, there are lots of other gasses in the air. When we breath in, our lungs fill up with all this gas. The lungs take the oxygen out of the air and breath out all the rest of the air our body doesn’t use.

In addition, we breath out carbon dioxide. It’s a gas our body produces when it makes energy. Just like how your body sweats when you play sports, your body makes carbon dioxide when it breathes.

Fish also use oxygen to keep their bodies running, but the oxygen that they use is already in the water.

Their bodies are built differently than ours. Humans and cats have lungs, while fish have gills.

That’s what I found out when I went to visit my friend Michael Berger. He’s a biologist at Washington State University.

You can see a fish’s gills when you look at their faces. They are lines on the sides of a fish’s face. The gills are also inside the fishes’ body, but those can’t be seen from the outside– just like our own lungs.

Berger explained that you can see a fish breathe in water because their face gets bigger when it’s full of water. Just like when you take a big bite of food.

First, the water goes into the fishes’ mouth and through the gills. As the water leaves the gills it returns to the ocean. Additionally, the carbon dioxide the fish creates is also removed as the water leaves the gills.

Berger shared a fun fact with me during our visit: Fish and other animals with gills are able to get oxygen to breathe because their blood flows through the gills in the opposite direction of water. If their blood flowed through the gills in the same direction as the water, the fish would not be able to get as much oxygen from it.

The gills are a like a filter and they collect all the oxygen the fish need to breath. After the gills pick up the oxygen, it is sent throughout their blood and fuels their bodies.

That’s why it’s important to leave fish in their home. Without water, they are unable to get the oxygen needed to stay happy and heathy.

If humans would like to breath underwater like fish, they can use a snorkel to experience life like a fish. Most snorkels kits include a mask and a mouth piece. The mouth piece is attached to a tube that reaches above water. That way, humans can keep breathing air while their mouth and nose are under water.

Sincerely,
Amanda Tomchick (and Dr. Universe)

Amanda Tomchick contributed this article. She is a student in the Edward R. Murrow College of Communication at Washington State University.

Dr. Universe: Why do birds have feathers? –Karthikeya, 7

Bird feathers are interesting. There are so many types, shapes, and colors. My friend Daniela Monk is a Washington State University professor who studies avian ecology, or the study of birds.

She told me about why the birds we know today have feathers and how they got them. Researchers believe that birds evolved from dinosaurs a very long time ago.

“One lineage of dinosaurs gave rise to birds,” Monk said.

Researchers around the world are finding dinosaur fossils that contain feathers. A fossil is the remains of a very old animal or plant that is preserved in a rock. From these fossils they are learning that some dinosaurs used to have feathers, but for other reasons than flying.

Monk said that early feathers likely provided those dinosaurs with insulation and enabled them to stay warm at night, just like in mammals where fur likely was selected for to keep them warm. Some of these feathered dinosaurs were small and needed to protect themselves from other animals that would harm them.

One possibility is that early feathers may have provided them with the ability of escaping. At first, these dinosaurs likely couldn’t fly very well and may have flapped their wings to better run up tree trunks or to glide from place to place.

Over a long period of time, some feathered dinosaurs became accomplished flyers. They became lightweight and airborne, like the birds we know of now.

Monk said that feathers even in dinosaurs may have had a function in addition to flight. They may have been used for communication. Birds have so many different colors and patterns of feathers, some are for protection while others are for attracting mates.

Male birds are typically very colorful while females are tan and brown so they can blend into their habitat and stay safe. Have you seen a peacock? Male peacocks have very colorful feathers, while the females have brown feathers.

If you find birds fascinating like I do, then maybe you can become a bird watcher. It’s simple. All you need do is watch the birds that live around your house and write down what you see and observe. How many different birds can you spot in your neighborhood?

Sincerely,
Bailey Campbell and Dr. Universe

Did you know not all birds fly? Penguins and Ostriches are flightless birds.

Bailey Campbell contributed this article. She is a student in the Edward R. Murrow College of Communication at Washington State University.

Dr. Universe: Why do we get tired? – Ellie S., 11, Maryland

Dear Ellie,

Sleep is one of the most important functions of our body. It helps us feel rested and gives us energy. Getting a good night’s sleep is important for our health. But when we don’t get enough sleep, or haven’t slept in a long time, we feel tired. » More …

Dear Dr. Universe: Why is it so cold up in the mountains if heat rises and it’s closer to the sun? –Andrea, 11

Dear Andrea,

You’re right. If we took a trip into the mountains, we would find that it felt a lot colder. It all has to do with our atmosphere. We may not always think about it, but we are basically living in a giant ocean of air. » More …

Sleep is one of the most important functions of our body. It helps us feel rested and gives us energy. Getting a good night’s sleep is important for our health. But when we don’t get enough sleep, or haven’t slept in a long time, we feel tired.

Humans went from learning how to fly a plane to putting a man on the moon in a little over 60 years. But the answer to your question goes even further back. It goes all the way back to the 1700s and actually started not with air, but with water.

Cats, humans, and fish all breath for the same reason. We need oxygen. Oxygen is one of the things our bodies use to make energy.

Just like the hungry feeling you get when you haven’t eaten, your body uses oxygen to keep everything running. Unlike the breaks you take between meals, the breaks you take between breathes are much shorter. Most people take about 12 breaths per minute.

Whenever there’s heavy rains or winds, butterflies seem to disappear. This is because butterflies hide when it rains. That’s what I found out from my friend David G. James who is an associate professor at Washington State University. He studies insects, including butterflies, in the Pacific Northwest.

Just like humans, us cats lose hair. Have you ever brushed your hair and found that some ends up on the brush? Sometimes human hair falls out. It is the body’s way of shedding, or getting rid of dead skin and hair.

Cats shed hair and whiskers. I love a good brushing. Maybe your cat likes getting brushed, too. Sometimes when it gets hot outside, I start losing some of my hair and it helps me stay cool.

People have wondered if Mars has life for a long time. About a hundred years ago, an astronomer named Percival Lowell looked through a telescope and thought he saw canals—a possible sign of water and life as we know it—on Mars.

Just like humans, us cats lose hair. Have you ever brushed your hair and found that some ends up on the brush? Sometimes human hair falls out. It is the body’s way of shedding, or getting rid of dead skin and hair. » More …

Dear Dr. Universe: What can you tell me about Mars? Is there life there? – Coleman, 10, Spokane, Wash.

Dear Coleman,

People have wondered if Mars has life for a long time. About a hundred years ago, an astronomer named Percival Lowell looked through a telescope and thought he saw canals—a possible sign of water and life as we know it—on Mars. » More …